How many bags of concrete do I need for 1 cubic yard?

One cubic yard of concrete requires exactly 45 bags of 80 lb concrete, or 60 bags of 60 lb concrete. Our calculator does this math automatically for any dimension.

How do you calculate concrete for a slab?

To calculate concrete for a slab, multiply the Length (in feet) by the Width (in feet) by the Depth (in inches divided by 12). This gives you the volume in cubic feet. Divide by 27 to get cubic yards.

What is the formula for calculating concrete in a cylinder or hole?

The formula for a cylinder is pi × radius squared × depth. Our tool automatically calculates this when you select the 'Hole / Column' option and input the diameter and depth.

Construction Utility

Concrete Volume Calculator

Calculate the exact amount of concrete needed in cubic yards, cubic meters, and pre-mixed bags for slabs, patios, and columns.

Measurement System

Length (ft)

Width (ft)

Depth / Thickness (in)

Total Volume Required

0.00

Cubic Yards

0.00 Cubic Meters

Estimated Pre-Mixed Bags

0

80 lb

0

60 lb

0

40 lb

Includes a 10% waste buffer.

What is a Concrete Calculator?

The Concrete Calculator by AJAI Tech Solutions is a powerful utility tool designed for contractors, builders, and DIY enthusiasts. Estimating the exact amount of concrete for a project can be tricky, and ordering too little or too much can delay your project and cost extra money.

Our tool instantly calculates the total volume of concrete required in Cubic Yards and Cubic Meters based on the dimensions of your slab, patio, footer, or columns.

Pre-Mixed Bags

Don't want to order a truck? The calculator tells you exactly how many 80 lb, 60 lb, and 40 lb bags of concrete you need to buy from the store.

Dual Measurement System

Switch seamlessly between Imperial (Feet & Inches) and Metric (Meters & Centimeters) formats with a single click.

How to Calculate Concrete Volume

Step 1: Choose the shape of your pour (Slab/Square or Hole/Column).
Step 2: Select your preferred measurement system (Imperial or Metric).
Step 3: Enter the Length and Width (or Diameter for a hole).
Step 4: Enter the Depth or Thickness (e.g., a standard patio is usually 4 inches deep).
Step 5: Click Calculate! The results automatically include a 10% safety buffer for spills and uneven subgrades.

Frequently Asked Questions (FAQs)

To make exactly 1 cubic yard of concrete, you will need:

45 bags of 80 lb concrete
60 bags of 60 lb concrete
90 bags of 40 lb concrete

Note: Our calculator adds a 10% waste factor to ensure you don't run short during your pour.

The formula to calculate concrete volume for a rectangular slab is Length × Width × Depth. If you are using feet for length/width and inches for depth, you must divide the depth by 12 to convert it to feet. Then, multiply them together to get Cubic Feet, and divide by 27 to get Cubic Yards.

In construction, subgrades are rarely perfectly level, forms may bow slightly, and some material is always lost to spillage or left in the mixer. Ordering exactly what the math dictates often leaves you short. A 5% to 10% buffer is an industry standard best practice.